This invention relates generally to optical networks and, particularly, optical networks that use optical power splitters.
In an optical network, a signal may be transmitted over an optical fiber. The signal may include a plurality of channels, each of a different wavelength. In order to multiplex the different channels onto the fiber, a multiplexer may be used. A demultiplexer is used to separate the multiplexed channels at a destination.
A power splitter may divide a channel into a plurality of distinct outputs. A signal, containing a single channel or multiple channels, may be divided by a splitter and delivered to several different destinations.
Amplification is required to compensate for propagation losses and loss of power of the signals due to splitting. The amplification of the optical signal is usually provided by erbium-doped fiber amplifiers.
Currently, there is particular demand for optical splitter devices for use in fiber-to-the-curb (FTTC) and fiber-to-the-home (FTTH) communication networks. These splitter devices facilitate the distribution of a common signal to multiple customers. However, a conventional splitter severely limits the transmission link length and the number of customers due to the natural signal loss associated with every splitting function.
Erbium-doped amplifiers can be used to compensate for such losses, significantly increasing the number of customers that receive the same signal. However, erbium-doped amplifiers are too expensive for this low-cost application. Also the broadband amplified spontaneous emission (ASE) noise generated in the amplifier degrades the signal-to-noise ratio, posing a limit on the number of customers serviced by the split signal.
Thus, there is a need for better ways to provide amplified splitting in optical networks.